Rotary metering pump



April 11, 1957 v. VON PLATO 3,

ROTARY METERING PUMP Filed Nov. 3.8, 1964 I N VEN TOR.

United States Patent 3,313,237 ROTARY METERING PUMP Vitalis von Plato, Springfield, Pa., assignor to Ryvon International Company, Philadelphia, Pa., a corporation of Pennsylvania Filed Nov. 18, 1964, Ser. No. 412,074 4 Claims. (Cl. 103--38) This invention relates generally to fluid pumps, and particularly to improvements in rotary fluid metering pumps.

A principal object of the invention is the provision of an improved rotary fluid metering pump of the type which operates without the use of valves.

Another object is to provide an improved pump of the character set forth comprising a casing with inlet and outlet ports and housing a rotatable piston and a reciprocable piston in contact with the rotatable piston, the contacting surfaces of the pistons being such that the rotation of the rotatable piston automatically causes longitudinal displacement of the reciprocable piston, thereby to open and close inlet and outlet ports in proper sequence.

Another object is to provide such a pump with means for changing the phase relation between the pistons thereby to selectively vary the rate at which liquid is metered by the pump.

Other objects of the invention will become apparent when the following description is read with reference to the accompanying drawing, in which:

FIGS. 1 and 2 are opposite end views of a pump constructed in accordance with the invention;

FIG. 3 is a longitudinal section through the pump, as indicated by line III-III in FIG. 1;

FIG. 4 is a fragmentary horizontal section through the pump, as indicated by line IV-IV in FIG. 3; and

FIG. 5 is an exploded view of the internal parts of the pump.

The following description is directed to the specific form of the invention illustrated in the drawing and is not intended to be addressed to the scope of the invention itself, which may be practiced in a varity of forms.

The exemplary pump constructed in accordance with the invention comprises an elongated casing in the form of a hollow cylinder 10, flanged at one end, as at 14. One side of the pump is provided with an outlet port 16, at the outer end of which is an O-ring 18 and a fitting 20. On the opposite side of the pump is an inlet port 22, at the outer end of which is an O-ring 24 and a fitting 26. Securing the fittings 20 and 26 in position is a band 28 embracing the cylinder and having opposite end portions secured together by a bolt 30.

Within one end of the cylinder 10 is a rotatable piston, generally designated 32, provided at one end with an oblique surface 34. Intermediate the ends of the piston 32 is a reduced diameter section 36 embraced by an O-ring 38. Formed on the piston 32 is a flange 40 and a tongue 42. The flange 40 is seated against the bottom of a counterbore 44 in the end of the cylinder 10.

At the flanged end of the cylinder 10 is a motor mount 46 provided with a cylindrical neck 48 fitted into the counterbore 44 and coacting with the bottom of the counterbore to secure the flange 40 against axial shifting movement. The mount 46 is secured to the flange 14 by means of a plurality of studs 50. Embracing the motor mount 46 is a clamp 52 for securing an electric motor 54. The motor shaft, designated 56, is connected to the tongue 42 by a pin 58.

Also disposed in the cylinder 10 is a reciprocable piston 60 provided with an oblique surface 62, and associated with the reciprocable piston 60 is means for fixing the same against rotation and operable for shifting the same axially relative to the rotatable piston 32, which means will now be described.

One end of the reciprocable piston 60 is provided with a slot 64 which is spanned by a pin 66 aflixed in the opposite side walls of the slot 64. Slidably fitted in the slot 64 is one end portion 70 of a link 68, which end 70 is in the form of a hook extending about the pin 66. The opposite end of the link 68 is connected to a pin 72 carried by one end portion of a member, generally designated 74. Fitted over the link 68 is a compression spring 75. Intermediate the ends of the member 74 is a reduced diameter portion 76 embraced by an O-ring 78. The member 74 is provided with a keyway 80 which slidably receives'one end portion of a screw 82 threaded into the cylinder 10. A terminal portion 84 of the member 74 is reduced in diameter and has turnably fitted thereover a cap 86 having a cylindrical body 88 and an end wall 90. The reduced diameter portion 84 is fitted with a collar 92 secured thereto by means of a rivet 94.

The drawing shows the condition of parts when both inlet and outlet ports are closed and the surfaces 34 and 62 are fully engaged. In the operation of the metering pump, the motor 54 is energized and its shaft turns the rotatable piston 32 in the direction indicated by the arrow, as a consequence of which the reciprocable piston 60 is cammed to the right against the action of spring 75, pin 66 being free to move within the hook 70.

Initially, as the reciprocable piston 60 moves to the right, the surfaces 34 and 62 separate to form there- =between a pumping chamber which, as it opens up and expands, draws a slug of liquid through the inlet port 22. As the rotatable piston 60 continues to turn, the fluid in the pumping chamber is carried around to the outlet port 16, and as the outlet port 16 is approached, the piston 68 moves back to the left under the influence of spring 75. Thus, the pumping chamber contracts, expelling the slug of liquid through the outlet port 16. Thereafter, as the rotatable piston 32 continues to turn, reciprocable piston 66 is again cammed to the right, whereupon the pumping chamber re-expands as it again approaches the inlet port 22, whereby to suck in another slug of liquid to be delivered to the outlet port 16.

In the condition illustrated in FIG. 3, a full slug of liquid is taken in and discharged from the pumping chamber since the surfaces 34 and 62 separate to afford a pump chamber of maximum size and then fully engage to fully close the pump chamber. But it will be noted that if the reciprocable piston 60 is initially set a slight distance away from the rotatable piston 32, the surfaces 34 and 62 will not fully engage, and the angular phase of the pistons relative to each other will be changed. Thus, the pumping chamber cannot fully close, and therefore cannot discharge a full slug of liquid through the outlet port 16. The farther reciprocable piston 60 is set away from the rotatable piston 32, the smaller the slug of liquid delivered by the pump per revolution thereof.

Reciprocable piston 60 is secured against rotation the link 68, and link 68 is secured against rotation by the member 74, which is slidably keyed to the casing by means of screw 82. Seepage past the member 74 is prevented by the O-ring 78.

To vary the output of the pump, the operator may turn cap 86 out a selected distance. Thus, member 74, link 68 and reciprocable piston 60 are shifted to the right, separating surfaces 34 and 62 more or less and changing the phase relation of the pistons.

What is claimed is:

1. In a rotary pump for metering liquids, the combination comprising a hollow cylinder provided with inlet and outlet ports, an axially fixed rotatable piston in said cylinder having an oblique surface at one end whereby said piston during its rotation alternately opens and closes said ports in sequence, a reciprocable piston having an oblique surface cooperating with the oblique surface of said rotatable piston for shifting said reciprocable piston axially in one direction during rotation of said rotatable piston, means yieldably biasing said reciprocable piston axially in the opposite direction, and means fixing said reciprocable piston against rotation and operable for selectively positioning said reciprocable piston axially relative to said rotatable piston thereby to vary the phase relation between said pistons and the rate at which liquid is metered, said last named means being adjustably fixed against axial shifting movement and provided with a lost motion connection with said reciprocable piston.

2. In a rotary pump for metering liquids, the combination comprising a hollow cylinder provided with inlet and outlet ports, an axially fixed rotatable piston in said cylinder having an oblique surface at one end whereby said piston during its rotation alternately opens and closes said ports in sequence, a reciprocable piston having an oblique surface cooperating with the oblique surface of said rotatable piston for shifting said reciprocable piston axially in one direction during rotation of said rotatable piston, a link having a sliding tongue and groove lost motion connection with said reciprocable piston, a member in said cylinder fixing said link and reciprocable piston against rotation and operable for selectively positioning said reciprocable piston axially relative to said rotatable piston thereby to vary the phase relation between said pistons and the rate at which liquid is metered, and means embracing said link and yieldably biasing said reciprocable piston axially in the opposite direction.

3. In a rotary pump for metering liquids, the combination comprising a hollow cylinder provided with inlet and outlet ports, an axially fixed rotatable piston in said cylinder having an oblique surface at one end whereby said piston during its rotation alternately opens and closes said ports in sequence, a reciprocable piston having an oblique surface cooperating with the oblique surface of said rotatable piston for shifting said reciprocable piston axially in one direction during rotation of said rotatable piston, means yieldably biasing said reciprocable piston axially in the opposite direction, and means fixing said reciprocable piston against rotation and operable for selectively positioning said reciprocable piston axially relative to said rotatable piston thereby to vary the phase relation between said pistons and the rate at which liquid is metered including a cap threaded over one end of said cylinder, and a member slidably fitted into said cylinder, said cap being connected to said member and being operable for shifting the same axially.

4. In a rotary pump 'for metering liquids, the combination comprising a hollow cylinder provided with inlet and outlet ports, an axially fixed rotatable piston in said cylinder having an oblique surface at one end whereby said piston during its rotation alternately opens and closes said ports in sequence, a motor directly connected to said rotatable piston for actuating the same, an O-ring embracing said rotatable piston to prevent seepage of liquid past said rotatable piston, a reciprocable piston having an oblique surface cooperating with the oblique surface of said rotatable piston for shifting said reciprocable piston axially in one direction during rotation of said rotatable piston, a link having a sliding tongue and groove lost motion connection with said reciprocable piston, a member slidably fitted into said cylinder and connected to said link, an O-ring embracing said member to prevent seepage of liquid past said member, means fixing said member, link and reciprocable piston against rotation, means embracing said link and yieldably biasing said reciprocable piston axially in the opposite direction, a cap threaded over one end of said cylinder and connected to said member, said cap being operable for shifting the same axially.

References Cited by the Examiner FOREIGN PATENTS 2/1954 Germany. 2/1955 Sweden. 

4. IN A ROTARY PUMP FOR METERING LIQUIDS, THE COMBINATION COMPRISING A HOLLOW CYLINDER PROVIDED WITH INLET AND OUTLET PORTS, AN AXIALLY FIXED ROTATABLE PISTON IN SAID CYLINDER HAVING AN OBLIQUE SURFACE AT ONE END WHEREBY SAID PISTON DURING ITS ROTATION ALTERNATELY OPENS AND CLOSES SAID PORTS IN SEQUENCE, A MOTOR DIRECTLY CONNECTED TO SAID ROTATABLE PISTON FOR ACTUATING THE SAME, AN O-RING EMBRACING SAID ROTATABLE PISTON TO PREVENT SEEPAGE OF LIQUID PAST SAID ROTATABLE PISTON, A RECIPROCABLE PISTON HAVING AN OBLIQUE SURFACE COOPERATING WITH THE OBLIQUE SURFACE OF SAID ROTATABLE PISTON FOR SHIFTING SAID RECIPROCABLE PISTON AXIALLY IN ONE DIRECTION DURING ROTATION OF SAID ROTATABLE PISTON, A LINK HAVING A SLIDING TONGUE AND GROOVE LOST MOTION CONNECTION WITH SAID RECPROCABLE PISTON, A MEMBER SLIDABLY FITTED INTO SAID CYLINDER AND CONNECTED TO SAID LINK, AN O-RING EMBRACING SAID MEMBER TO PREVENT SEEPAGE OF LIQUID PAST SAID MEMBER, MEANS FIXING SAID MEMBER, LINK AND RECIPROCABLE PISTON AGAINST ROTATION, MEANS EMBRACING SAID LINK AND YIELDABLY BIASING SAID RECIPROCABLE PISTON AXIALLY IN THE OPPOSITE DIRECTION, A CAP THREADED OVER ONE END OF SAID CYLINDER AND CONNECTED TO SAID MEMBER, SAID CAP BEING OPERABLE FOR SHIFTING THE SAME AXIALLY. 